Enews - Spring 2010

Spring has come surprisingly early to the New England states. People are already out raking leaves that escaped them in the fall and preparing their gardens for planting. In this issue, we discuss mulches, milestones, maintenance, and the many nutrients in compost. For more articles and information, please visit our site at www.AgresourceInc.com.

Message from the Product Sales Staff

2010 marks a few milestones for Agresource and we want to thank everyone with whom we do business for their support and for the opportunities that we have had and expect will continue. We have sold well over 1,000,000 cubic yards of a variety of compost, soil, and mulch products. We have gained considerable experience over many years and we now have combined sales staff experience totaling over 50 years. What this means is that we will continue to be a reliable source for information about compost, soil, and mulch products so that our customers will remain the most informed consumers.

Even in a less robust economy, we look forward to providing quality products and first-rate service in 2010. Thanks again from the product sales staff at Agresource.

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The Evolution of Mulches in New England

The primary horticultural values of mulch include holding moisture in the soil, controlling weeds, moderating soil temperature, preventing erosion, and controlling diseases.

Over the last decade, it could easily be argued that mulch selection in New England has more to do with appearance than its horticultural purpose. At one time, pine mulch was the product of choice unless you wanted a higher-end look, and then you could use hemlock mulch. At some point, “red” mulch was most popular and red-colored mulch seemed to be everywhere. As the popularity of red mulch began to wane, darker mulch gained favor and indeed, dyed black mulch is becoming prevalent.

With the onset of dyed mulch came the use of waste wood or recycled wood in mulch—sometimes blended with pine or spruce bark or often sold as a stand-alone product. Increased costs for natural bark mulch resulted in increased use of more recycled wood. As more recycled wood was used, mulch with very high carbon content was created.

Many are now witnessing the problems associated with mulch that is very high in carbon. Landscapers have seen the results of nitrogen-robbing mulch as it diminishes annual and perennial plant growth. They are asking for better mulch that does all that mulch is required to do in terms of weed-suppression and adding attractiveness, but that also helps to improve soil and facilitate plant growth. Research conducted by Daniel Herms, John Lloyd, and Benjamin Stinner at the Ohio Agricultural Research and Development Center (Ohio State University) has shown that compost, typically low in carbon when used as mulch, can have major effects on improving soil fertility and plant growth. Click here for more information on this research.

While appearance is still a factor, professionals and non-professionals alike recognize that the quality of mulch—and not just the look—is vitally important.

Compost Takes on a Stronger Role in Sustainable Landscape

Sustainable landscaping is broadly defined and includes a variety of practices. Included among the various sustainable practices are the use of integrated pest management (IPM) techniques to reduce pesticide usage, careful application of nutrients and fertilizers, selection of native plants, and various water and energy conservation practices.

Compost has taken a central role in sustainable landscaping maintenance because it is has gained significant recognition as a recycled product that can be used to meet many of the objectives of sustainable design and maintenance.

Compost’s role in enhancing the biological activity in soil and in suppressing soil-borne disease has received increasing recognition in recent years and is widely appreciated by professionals and non-professionals alike.

Organic matter provided by composts can increase soil microbial populations and their activity. This activity can lead to the suppression of a variety of diseases and allows for a reduction or elimination of the use of herbicides and pesticides.

Composts provide a variety of nutrients including Nitrogen, Potassium, and Phosphorus (N-P-K) that are released slowly. Nutrients provided by compost, such as nitrogen, can be quantified and therefore allow for an informed reduction in use of fertilizers. Many micro-nutrients that are often not included in traditional fertilization programs are also provided by compost. These “vitamins” for the soil are evident in the lasting verdant turf and thriving perennials and annuals witnessed after using compost.

The improved ability of soil to hold water after compost has been incorporated is widely recognized. Soil scientists have determined that for every 1% increase in soil organic matter content, every cubic foot of soil will hold about one-third of a gallon more water. This has added up to significant savings for property owners who have used compost and seen cost-reductions in their water bills from less irrigation.

In recent years, we have seen a surge in sustainable landscape maintenance practices. Many professionals at colleges and municipalities, as well as commercial property owners are using compost on an annual basis in planting beds for topdressing turf. Homeowners are increasingly interested in more sustainable landscape maintenance programs that protect the environment and reduce overall maintenance costs. Many examples of compost use as part of sustainable landscaping practices can be seen in the Project Highlights section at www.Agresourceinc.com.

Compost as a Good Source of Nutrients

Compost is most often recognized for its value as a soil amendment that provides organic matter. The importance of soil organic matter in improving soil structure, increasing biological activity, and helping to protect the environment is well established and appreciated. However, compost amendments also provide significant sources of slow-release nutrients.

Compost is an excellent source of Nitrogen, Phosphorous, and Potassium (NPK), as well as a wide range of other necessary plant nutrients and trace elements. Although the nutrients in various composts are generally present in low concentrations compared to most fertilizers, composts are added to soils at higher rates and thus can provide for a significant portion of the plant's needs.

The concentration of nutrients will vary considerably based on the content of the feed stocks used to make a particular compost. The N-P-K ratio of compost varies from 1.1-0.02-0.2 to 3.5–0.4–0.4. Total Nitrogen ranges from 5 lbs. per cubic yard of compost to as much as 13 lbs. per yard. Extractable micro-nutrients in compost range from 2-10 mg/kg for Boron, 30-250 for Manganese, 5-50 for Zinc, 0.3-5 for Copper, and 1.5-1- for Iron.

Generally, biosolids composts are higher in all nutrients, and leaf and yard waste composts tend to be on the lower end of the scale. Farm-based compost (made with manure) varies considerably and, depending on the manure-type, may fall outside of the ranges provided above.

Unlike most fertilizers, the nutrients provided by compost applications are released slowly and thus not immediately available. As a consequence of their organic form, the nutrients are not readily leached from the root zone after periods of heavy rain. Nutrients are released from the compost as the organic matter decays slowly in the soil.

Of course, the role that compost plays in boosting the Cation Exchange Capacity of soil thereby making nutrients more available to plants must be re-emphasized as a central benefit of compost. Essential nutrients provided by compost applications can be significant and should be taken into account with any landscape construction or maintenance program.